Cauda equina schwannoma with concomitant intervertebral disc herniation: A case report and review of literature.

The coexistence of lumbar intervertebral disc (IVD) herniation and cauda equina schwannoma in symptomatic patients is uncommon. We experienced a case with a surgically treated cauda equina schwannoma with concomitant lumbar IVD herniation (L2/L3); both were relatively small but presented with painful symptoms in combination. A 45-year old man complained of low back pain and right anterior thigh pain six months prior to surgery. He underwent conservative treatment; however, his pain suddenly worsened three months before surgery, with abnormal sensations and pain in his right buttock and posterior thigh. A magnetic resonance imaging (MRI) scan revealed an L2/L3 disc herniation extruding to the center of the lumbar spinal canal and compressing the thecal sac. Incidentally, an intrathecal tumor was suspected, and enhanced MRI revealed a round tumor measuring 10-mm in diameter at the L2/L3 intervertebral level, which was uniformly enhanced by gadolinium chelate, radiologically diagnosed as a schwannoma. Microscopic discectomy and tumor resection were performed and the patient's symptoms disappeared immediately. Schwannoma is generally slow-growing, and usually asymptomatic when the tumor size is small. Therefore, we suspected that the tumor occasionally impinged on the left L3 root with L2/3 IVD herniation, leading to acute worsening of the patient's symptoms. Altogether, in case of tumor in patients undergoing conservative treatment for cauda equina schwannoma, we should consider that symptoms can acutely worsen with the occurrence of lumbar IVD herniation.